@node longjmp, misc
@subheading Syntax

@example
#include <setjmp.h>

void longjmp(jmp_buf env, int val);
@end example

@subheading Description

This function reverts back to a CPU state that was stored in @var{env}
by @code{setjmp} (@pxref{setjmp}).  The state includes all CPU registers,
so any variable in a register when @code{setjmp} was called will be
preserved, and all else will be indeterminate.

The value passed as @var{val} will be the return value of @code{setjmp}
when it resumes processing there.  If @var{val} is zero, the return
value will be one. 

@subheading Return Value

This function does not return.

@subheading Portability

@portability ansi, posix

@subheading Example

@example
jmp_buf j;
if (setjmp(j))
  return;
do_something();
longjmp(j, 1);
@end example